The excessive use of synthetic chemical products for controlling agricultural fungal pests has led to negative consequences for both the environment and human health. This has created the need to seek new natural alternatives that are more environmentally friendly, promote food safety, and ensure health. The objective of this research was to obtain essential oils from ten Piper “cordoncillo” species and conduct spore germination inhibition assays against the phytopathogenic fungi Aspergillus niger and Alternaria alternata. The results obtained using the hydrodistillation method yielded ten samples of essential oils from Piper “cordoncillo” (P. aequale, P. aduncum, P. barbicuspe, P. sp. , P. mite, stellipilum, P. strigosum, P. hispidum, P. macerispicum y P. poporense), all of which showed activity in inhibiting the spore germination of Aspergillus niger and Alternaria alternata. S...